Reviewed by John M. Grohol, Psy.D. on August 27, 2010
Researchers have discovered that moderate exercise, such as walking for 40 minutes three times a week, can enhance cognitive skills.
Specifically, the exercise can improve the connectivity of important brain circuits, mitigate declines in brain function associated with aging and improve performance on cognitive task.
Researchers followed a group of “professional couch potatoes,” composed of 65 adults ages 59 to 80, who joined a walking group or stretching and toning group for a year.
…. the study looked at activity in brain regions that function together as networks.
“Almost nothing in the brain gets done by one area – it’s more of a circuit,” said University of Illinois psychology professor and Beckman Institute Director Art Kramer, who led the study.
“These networks can become more or less connected. In general, as we get older, they become less connected, so we were interested in the effects of fitness on connectivity of brain networks that show the most dysfunction with age.” …..
Neuroscientists have identified several distinct brain circuits. Perhaps the most intriguing is the default mode network (DMN), which dominates brain activity when a person is least engaged with the outside world – either passively observing something or simply daydreaming.
Previous studies found that a loss of coordination in the DMN is a common symptom of aging and in extreme cases can be a marker of disease, Voss said.
“For example, people with Alzheimer’s disease tend to have less activity in the default mode network and they tend to have less connectivity,” she said.
Low connectivity means that the different parts of the circuit are not operating in sync. Like poorly trained athletes on a rowing team, the brain regions that make up the circuit lack coordination and so do not function at optimal efficiency or speed, Voss said.
In a healthy young brain, activity in the DMN quickly diminishes when a person engages in an activity that requires focus on the external environment.
Older people, people with Alzheimer’s disease and those who are schizophrenic have more difficulty “down-regulating” the DMN so that other brain networks can come to the fore, Kramer said.
Previous studies have found that aerobic exercise can enhance the function of specific brain structures, Kramer said. This study shows that even moderate aerobic exercise also improves the coordination of important brain networks.
“The higher the connectivity, the better the performance on some of these cognitive tasks, especially the ones we call executive control tasks – things like planning, scheduling, dealing with ambiguity, working memory and multitasking,” Kramer said….
Source: University of Illinois
READ IN FULL at http://psychcentral.com/news/2010/08/27